Pregnancy and Prenatal PAHs and other Environmental Exposures and Breast Cancer
Breast Cancer & the Environment Research Program
Columbia University Mailman School of Public Health
Columbia University Medical Center
NIEHS Grant: U01ES026122
Other Community and Academic Partners:
West Harlem Environmental Action (WE ACT) For Environmental Justice
The Ohio State University Wexner Medical Center
University Health Network
Lovelace Respiratory Research Institute
Mt. Sinai Hospital
Accumulating human and animal data support the hypothesis that breast cancer risk is modified during key windows of susceptibility. These include the prenatal and pregnancy windows, during which time the breast changes in structure and function and breast cells rapidly proliferate. The Columbia Center for Children's Environmental Health (CCCEH) birth cohort is one of the few cohorts in the world with extensive biospecimens and environmental monitoring data that are reflective of the contemporary environment collected during the pregnancy time period for mothers and during the prenatal period for children. In addition to repeated urine and blood samples in both mothers and daughters, the mothers wore a small backpack containing a personal ambient air monitor during the daytime hours for two days to measure personal air pollution exposures during their pregnancy. The cohort is composed exclusively of Hispanic Dominican and African-American women residing in New York City and their children, who were born in the Bronx or Northern Manhattan between 1998 and 2006 (N=543 mothers currently being followed of whom 52.5% (N=285) are mother-daughter dyads). These families reflect the local community, as well as represent the population subgroups experiencing a rapidly increasing breast cancer incidence in young women.
The research team is building on this unique birth cohort specifically by measuring breast tissue characteristics and breast density, a strong intermediate marker of breast cancer risk through optical spectroscopy (OS) for all mothers and daughters and mammography for mothers over 40 years of age. They are also collecting clinical measures of breast tissue characteristics, anthropometry, and biospecimens in the now adolescent girls (age range 10-16 years) and their mothers. There are few human studies in which exposures to the same pollutants have been measured to allow for simultaneous evaluation of their effect on both the mother's breast cancer risk and that of her daughter.
The research team is focusing on polycyclic aromatic hydrocarbons (PAHs), byproducts of combustion classified as possible carcinogens by IARC and the U.S. EPA. They are coupling the human study with robust mouse experiments investigating the role of airborne PAH exposure during gestation on altered mammary tissue and systemic DNA methylation and expression of genes important to DNA repair and apoptosis in mothers, their offspring, and their grand-offspring. Researchers also are investigating the role of PAHs on PPARγ gene regulation, a gene important to lipid metabolism and associated with breast cancer risk, as well as examining mammary tissue alterations in both the mouse and human models and comparing genes that are methylated in humans with higher PAH exposure across both model systems. The researchers also are building on the CCCEH Community Outreach and Translation Core to integrate research findings with messages about environmental exposures and breast cancer prevention in the study participants and larger community.